George t



(No Model.) 4

. I G. T. WARWICK. PROCESS OF FORMING BACK BONES. AND REAR FORKS 0FBIGYGLES FROM A SINGLE BLANK. No. 397,405. Patented Feb. 5, 1889.-

N. PETERS, PholoUhngn-pphar, Washinglcn. n. c.

' limrnn STATES arnnr tries.

GEORGE T. \VARlVICK, OF SPRINGFIELD, MASSACHUSETTS, ASSIGN OR TO THEIVJXRWICIK CYCLE MANl l AC-TI RING C(UIPANY, OF SAVE PLACE.

PROCESS OF FORMING BACKBONES AND REAR FORKS OF ,BICYCLES FROM A SINGLEBLANK.

SPECIFICATION forming part of Letters Patent No. 397,405, dated February5, 1889'. Application filed March 23, 1888. Serial No. 268,297. (Nomodel.)

To aZZ whom it may concern.-

Be it known that 1', GEORGE T. \Vkawick, a citizen of Great Britain,residing atSpringfield, county of llzunpden, and State of Massa- 5chusetts, have invented certain new and useful Improvements in the Artor Process of Making integrally from Sheet Metal, for Bicycles andsimilar Vehicles, llackboncs and their Rear-'Wheel Forks and Front-Wheel1o Forks and the Hollow Ileads Thereof; and I do hereby declare that thefollowing is a full, clear, and exact description. of the invention,which will enable others skilled in the artto which it appertains tomake and use the I 5 same.

Heretofore the a1iove-referred-to backbone and front-wheel fork forbicycles have been. made, respecth ely, by forming said backbone from ametallic tube, and subsequently attachin g a separatelyonade rear-wheelfork by brazing or other suitable method, and the frontwheel forks ofthe machine and the head for said forks have been made in separate partsand secured together in substantially the 2 5 manner above referred torelative to the roan wheel fork and the backbone.

The object of my invention is to simplify the construction of said partsby reducing the number of pieces required to be made and united to formeach one of the abovementioned bicycle parts, and thus greatly reducethe cost of manufacturing the same.

In the drawings forming part of this specification, Figure 1 is a sideelevation of the backbone and rear-wheel fork of a bicycle constructedby the employment of my improved process. Fig. is a view of the side ofthe backbone and rear-wheel fork,wl'1ich, when the backbone is embodiedin a machine,

40 is opposite the periphery of the front wheel thereof, this figureshowing only that portion of the backbone immediately :uljoining therear-wheel fork, and showing also the seam or joint line of thebackbone. Fig. 3 is a side elevation of the front-wheel, fork and thehead thereof; and Fig. 4: is a similar view to Fig. 3, but showing saidfront-wheel fork and its head as it appears looking at the machine fromits rear wheel forward. Fig. 5 is a plan View of a sheet-metal blankfrom which the backbone and fork, Figs. 1 and 2, are constructed. l ig.o is a longitudinal section on the line at a, Fig. 5. Fig. 7 is atransverse section of one of the fork-legs. Fig. 8 is a transversesection through the backbone at some point between the rear-wheel, forkand the upper end thereof. Fig. 9 is a plan view of a sheet-metal blankfrom which the frontwheel fork, lfiigs. i3 and 4, and thehead there offormed.

In carrying my invention into effect for the manufacture of either thebackbone and the rear-wheel fork or the front fork and the head thereofI first cut from a sheet of metal, preferably of steel, a blank,substantially as illustrated in Figs. 5 or J, of suitable size and formfor the construction of said parts. I refer to the said two parts of abicycle in conjunction liiecause identically the same pro cess ofmanufacture is applicable to each one of them, for the fl'0llt-\\'l160lfork and its head, made of a single piece of metal, represents,substantially, a portioi'i of the backbone adjoining the rear-wheel forkthereof, but somewhat larger in diameter and having the fork partslonger and larger than those of the rear wheel.

In furthercarrying my inventioninto effect I impart to said backbone andfork-head a cylindrical tubular form by bending the said blank parts,Figs. 5 and 9, which are indicated by the letters a and 1), therebyforming the tubular backbone c and the tubular front-wheel fork-head (I,said tubular parts being formed on a suitable mandrel or former, wherebythe S5 opposite edges of said tubular parts are brought intojuxtaposition, thus forming a longitudinal seam, 3, (shown on thebackbone part in Fig. i and on the fork-head (I, Fig. 4,) and I thenrigidly attach said adjoining 9o edges by brazing, soldering, or othersuitable means, and finally finish said parts by giving them therequireil. form, that of the backbone being illustrated in Fig. 1, andthe form of the t'ork legs l. of the front-wheel. fork and 5 5 of therear-wheel fork being half-round or curved in cross-section, asillustrated in. Fig. 7, whereby said fork-legs are given the requisiterigidity and strength. The said adjoining edges of the blanks a and h,forming the seam 3 of said parts, may be either butted, lapped,orotherwise suitably jointed, and then secured as aforesaid.

In Figs. 3 and at an opening, 6, of rectangular form, in the rear sideof the head (6 of the front-wheel. fork,is indicated,which serves theusual purpose of providing for the insertion of the backbone-spindleinto said forkhead, that portion of the ordinary backbonehead betweensaid spindle and the backbone passing through said opening 0 in theusual manner. The usual perforations, 7 and 8, respectively, are made inthe lower ends of the fork-legs'i c and 5 to receive the axles of thefront and rear wheels of the machine. The said sheet-metal blank (l,f]Oll1 which the backbon e and the rear-wheel fork are made, is madepreferably of such varying thickness as is illustrated in Fig. 6, inorder that the back- 4 bone and fork parts thereof shall possess thegreatest strength where the strain thereon is excessive. To that end Iprefer to construct the backbone of a diminishing thickness from itsupper end, 8, to its junction at f with the rear-wheel fork, and thenincrease the thickness of that part of the blank at i, which forms thelegs of the fork, tapering said leg parts slightly, shown, to a pointnear the lower extremities thereof, at 0, and then increasing thethickness of the latter at z to provide a better bearing for the axle ofthe wheel; and so far as the parts of the blank I) are concerned, whichenter into the construe tion of the front fork-legs, 4, they are givensubstantially such varying thiekn esses as are above described relativeto the fork parts on the lower end of the backbone.

Having fully described my invention, what I desire and claim to secureby Letters Patent 1s The within-described process for making thebackbone and the rear-wheel fork of a bicycle from a single piece ofsheet metal,-

which consists in cutting a blank of proper form from said sheet metal,having a part to form said backbone and parts to form the two legs ofsaid fork, and then imparting a cylindrical tubular form to saidbackbone part and rigidly uniting the meeting edges thereof, andimparting a curved form in crosssection to said fork parts, and finallyperforating the fork-legs to receive an axle and shaping and finishingthe sheet-metal piece so made, substantially as set forth.

GEO. T. \VARWICK. Witnesses:

ll. A. CHAPIN, G. M. CHAL'IBERLAJN.

